A spider bite is an injury resulting from the bites of spiders or other closely related arachnids. Spiders are active hunters and rely heavily on their bites to paralyze and kill their prey before consuming it. They also bite in self-defense. While many spiders will never attack animals larger than themselves, some—e.g. , Atrax robustus—exhibit a rather aggressive behavior and will stand their ground when approached by larger animals.